1. Field of the Invention
This invention was made under contract with or supported by the Electric Power Research Institute.
Sodium-sulfur solid electrolyte batteries provide numerous advantages over other types of batteries. The sodium and sulfur are low molecular weight and therefore provide greater power storage capability per unit weight as compared to lead or nickel batteries. In addition, the active materials can be stored outside of the cell and be circulated through the active cell. Thus, theoretically a small battery cell can have infinite storage capacity. However, due to the peculiar nature of the battery in having liquid electrodes and a solid electrolyte, many technological problems are encountered in developing a battery which is stable, efficient, and safe.
One of the difficulties with the sodium-sulfur battery is high internal resistance. It is therefore desirable to maximize the solid-liquid interface. It is also desirable to reduce the diffusion path length in the liquid reactants. Other considerations are ease of heat transfer, fabrication, current collection in the sulfur cell and ease of introduction and removal of the anolyte and catholyte.
2. Description of the Prior Art
U.S. Pat. Nos. 3,647,542 and 3,661,644 each describe honeycomb matrices for batteries. U.S. Pat. No. 3,839,090 describes a current collector.
See also U.S. Pat. Nos. 3,423,243, 3,661,644 and 3,647,542.